1. Field of the Invention
The present invention relates to an auxiliary steering system for a vehicle, suitably used for improving a vehicle's dynamic performance.
2. Description of the Related Art
An auxiliary steering system is usually designed to steer front wheels and/or rear wheels of the vehicle in addition to main steering of the front wheels by a steering maneuver of a steering wheel, whereby a vehicle's dynamic performance is improved in a desired manner.
A typical example of a conventional auxiliary steering system for a vehicle is disclosed, for instance, in Japanese Patent Application Laid-Open Publication No. 63-251374. In the disclosed auxiliary steering system, auxiliary steer angles of front wheels and rear wheels .delta..sub.f, .delta..sub.r are calculated from the following equations respectively. EQU .delta..sub.f =K.sub.f .theta.+T.sub.f (d/dt).theta. (1) EQU .delta..sub.r =K.sub.r .theta.+T.sub.r (d/dt).theta. (2)